1. Field of the Invention
The field of the invention is primarily that of removable tap holders adapted for use with tapping attachments. The invention is particularly concerned with removable tap holders having a built in torque release clutch. The components of such a clutch are of relatively small diameter since they are built into the removable tool holder. The improvements of the invention reside primarily in a torque release clutch having this adaptation.
2. DESCRIPTION OF THE PRIOR ART
The herein inventor's prior U.S. Pat. No. 3,472,347, is directed to a removable tool holder with built in clutch adapted for utilization in a tapping attachment. The clutch that is utilized in the herein invention is of the type shown in this inventor's prior U.S. Pat. No. 3,472,347, and also in the inventor's prior U.S. Pat. No. 3,791,756.
The patents referred to constitute the most pertinent prior art within the knowledge of the herein inventor. The prior art removable tap holder with built in clutch lacks a certain characteristic present in the improvement of the herein invention. Because of the relatively small size of the built in clutch, the spring which acts on one of the clutch members must be a relatively heavy spring. In the known devices, the clutch is disengaged and there is still some limited engagement between the teeth on the clutch members which may be in the amount of 0.015 to 0.020 thousandths. This engagement of the clutch faces is necessary to bring about re-engagement of the clutch on reverse rotation. This engagement, however, particularly in view of the relatively heavy spring, causes undesired wear to occur as between the teeth on the clutch faces. This disadvantage of the known prior art devices is overcome by the improvements of the herein invention.